Amphibian population declines and deformities due to various causes including land use change, viruses, and fungi. Links to USGS press releases, answers to FAQs (HTML and PDF versions) and photos with downloadable files.

They're abundant in this area, but hard to count reliably. We outline a procedure for estimating the population sizes so that we can determine whether they're increasing or dwindling. We must both listen for their calls and visually confirm them.

Links to information on species of frogs, toads, and salamanders located in the southeastern United States and the U.S. Virgin Islands, with information on appearance, habitats, calls, and status, plus photos, glossary, and provisional data.

Fact sheet (PDF format) on amphibians in Olympic National Park and overview of the habitat, the decline in populations, and rare amphibians in the Pacific Northwest including the giant salamander and tailed frog.

We removed non-native fish from a section of the river and the endangered native species humpback chub increased in abundance. But it is not yet clear that decreased competition explains the rebound in population.

Background information and genetic sequencing data for more than 1,000 individual field isolates of the fish virus Infectious Hematopoietic Necrosis Virus (IHNV) collected in western North America from 1966 to the present, updated annually.

Papers from a 1999 symposium on the possible effects on water resources and the environment of large agricultural feeding operations for pigs, chickens, and cattle, with links to other meetings, bibliography, and research studies. (Also as PDF files)

Wildlife you see in a national park or other reserved area don't know about the park boundary. Bobcat, martens, mink, and moose need different types of living space and habitat. Development outside the park affects their ability to inhabit the park.